1. Field of the Invention
This invention pertains generally to thermal radiators and more specifically to thermal radiators on depolyable equipment modules for satellite application.
2. Description of the Related Art
Organizations developing small satellites are faced with dense packaging of on-board equipment and deploying large and light solar arrays from small stowage volumes. The trends in electronics miniaturization, denser component packaging, increasing solar array deployed area-to-stowed volume ratio, and even smaller and lighter satellites and launch vehicles are resulting in a higher ratio of power dissipation to satellite body volume. Electrical power dissipation must ultimately be thermally radiated from a satellite to the space sink by way of external radiating surfaces (radiators), and the inviolate laws of physics dictate the watts per unit area upper limit.
Deployable thermal radiators are components of conventional, but "cutting edge" technology, temperature control systems. In addition to the usual deployment mechanisms, there must be a means to connect radiator and mainbody thermally, conductively either across the rotating joint-hinge line materials (high conductance is not to be expected), or via heat pipe plumbing between radiator and mainbody through a flexible joint. Deployed radiators and associated plumbing are 100% added mass and carry a high total cost per unit area. To minimize mass and cost, they are usually rather precisely sized for their role as part of a conventional satellite active temperature control system. Excess radiator area to provide for a comfortably large hot case margin is a costly luxury not usually or readily obtained. Fluid loops within lightweight deployed radiators are more susceptible to failure as a result of micrometeorite penetration than heat pipes within, and protected by, satellite structure.